Trying to catch up with a series like Torchwood: Miracle Day is a bit like trying to get up to speed in Sumerian mythology in just 10 minutes. Actually, it's worse, since the cross-series references that produce a warm bolus of joy inside true devotees mean you don't have only one belief system to disentangle. If Enki, the Sumerian deity of crafts, occasionally popped up on Mount Olympus, in ways that were critical to a full understanding of later Greek theology, then you'd be a bit closer to it. I don't have the time (or the inclination frankly) to engage in such an arduous field of scholarship, so I might as well confess right now that I don't have the faintest idea what Phi-Corp is or what the Trickster's Brigade are up to or how Jack keeps skipping around between different time dimensions. What I can say, on just two minutes' acquaintance with the current series, is that it has a great central idea. Everybody has stopped dying, one of those monkey's paw miracles that looks like a blessing but turns out to be a catastrophe. Jack and his Torchwood cronies are currently trying to find out why it's happened, though the urgency of their quest doesn't appear to prevent Jack spending quite a bit of happy downtime with a fetching young Italian immigrant called Angelo.

I didn't quite get that either, to be honest. At one moment, Jack's being kidnapped by Gwen, because her family are being held hostage by sinister forces. At the next, he's just off the boat in Prohibition America, debating theology with Angelo. You simply have to go with the flow, I guess, and cling on to whatever floats by in the current. In this case, the buoyancy aids included a teasing gay seduction, cleverly conducted by means of a shared heterosexual fantasy, and Gwen's anguished monologue about how the thrills of saving the world from aliens had made her overlook her real priorities as a mother and a wife (the career is so much easier on philandering bisexuals). In common with a lot of recent television science fiction the ratio of running about being chased by monsters to plangent moments during which everyone gets tears in their eyes was heavily tilted in favour of the latter.

It's taken as a benchmark of maturity by real aficionados, I think, that difficult emotions and tricky subjects (the homophobia of the Catholic church, in this case) get more screen time than writhing alien biomorphs. Indeed, last night's episode was as tremulous with feeling as a Warner Brothers weepie, though suffered a little (as these things often do in my experience) from the fact that fantasy always offers a secret trap-door escape in a way that real life does not. Real emotions take their power from the intractability of human experience – of death above all – and if you can dodge away from an unmendable event down a wormhole in time it's difficult to get too worked up about anything. For the moment, it's supposed to add edge to the drama that Jack has become mortal for the first time in his existence, and actually has a life to lose. But you simply assume that there would be some kind of loophole in the fine print if it ever really came to the crunch. That said Torchwood does do some strange and intriguing things with its basic premise: at one point here (during the flashback sequence), Jack was submitted to a kind of recurring martyrdom, repeatedly killed and repeatedly coming round again as his Italian neighbours tested his miraculous imperviousness to damage. A bizarre mix of Catholic iconography, torture porn and gay soap opera romance, it left Sumerian mythology looking positively vanilla by contrast.

There was never anything untoward in a British Pathé newsreel, an archive further explored in The Story of British Pathé, which vaguely hinted that it would be about the distinctive voice of Bob Danvers-Walker but then turned out to be just a string of vaguely related clips held together by loose chronology. Nothing terribly wrong in that, given the pleasures of guileless patriotism and male condescension the material offers. But not for the first time I found myself wondering about the standard length of BBC4's documentaries, excellent as they often are. An hour is a long time to fill on screen. There were some nice extras here, including an interview with two women who'd grown up living in a tent on Folkestone foreshore (a hardship breezily presented as a bracing adventure by Pathé). But there was quite a bit of padding too. Sometimes the discipline of a shorter slot means you can get more in.